Abstract
Purpose: :
To characterize transcriptional responses of corneal epithelial cells after herpes simplex virus (HSV) infection and identify crucial signaling events via approaches utilizing network analysis.
Methods: :
Immortalized human corneal epithelial cells were infected with HSV-1 strain KOS. The transcriptional responses of 30000 genes were analyzed using whole human genome chip(Agilent). Molecular networks of HSV-induced genes were constructed using GeneSpring GX7.3.1 and Ingenuity Pathway Analysis(IPA) . Representative network cascade was verified using real time-RT-PCR and ELISA.
Results: :
ANOVA analysis of HSV-induced-transcriptome identified 412 genes (P<0.05, 2< or 0.5> threshold). The gene set was used to probe HSV-responsive signal transduction pathways. Pathway analysis using Kyoto Encyclopedia of Genes and Genomes identified MAP kinase signaling, cytokine-cytokine receptor interaction, focal adhesion, and carcinogenesis. Network analysis predicted IL-6 and VEGF as crucial nodes of signaling events (significance score 19).HSV-stimulated-cytokine analysis by ELISA kinetically verified their induction. Neutralization of IL-6 significantly suppressed HSV-induced-VEGF secretion.
Conclusions: :
Comprehensive transcriptional analysis identified IL-6 and VEGF as presumable key modulators in HSV infected corneal epithelium. Since VEGF has been already recognized as an important player in stromal herpetic keratitis, up-regulation of VEGF in HSV corneal epithelial infection suggests very early participation of VEGF in the pathogenesis of herpetic keratitis.
Keywords: cornea: epithelium • cornea: basic science • cornea: clinical science